1. Field of the Invention
The present invention relates to a battery pack, and more particularly, to a remaining battery life prediction device configured to predict a remaining battery life of, for example, a lithium-ion rechargeable battery.
2. Description of the Related Art
It is required for rechargeable batteries that have been used in various devices represented by mobile devices to be provided with a battery management system configured to manage charging and discharging of the battery. An operating time of a device needs to be grasped more accurately particularly when the device is being operated, and a remaining battery life prediction device has been used for accurate detection.
A battery pack including a related-art remaining battery life prediction device is illustrated in FIG. 6. A remaining battery life prediction device 20 includes a CPU 21 configured to perform signal processing calculation, a RAM 22 to be used in the signal processing calculation, an ADC 23 configured to detect a battery voltage obtained by converting, with a level translator 26, a battery voltage of a rechargeable battery 7 per one cell, an ADC 24 configured to detect a voltage generated at a current sensing resistor 6 for detecting a current of the rechargeable battery 7, and a non-volatile memory 25 configured to hold data on, for example, characteristics of a battery in advance. The remaining battery life prediction device 20 obtains a remaining battery life based on a voltage of the rechargeable battery 7, a transferred charge amount obtained through coulomb counting with a current value of the rechargeable battery 7 measured with the use of the current sensing resistor 6, and the like. In order to predict a remaining life with high accuracy, it is required to measure the voltage and current of the rechargeable battery 7 with high accuracy.
When attention is paid particularly to the current measurement, the current sensing resistor 6 is required to have a resistance value with high accuracy.
In order to predict a remaining battery life with high accuracy with the battery pack including the related-art remaining battery life prediction device 20, the highly accurate current sensing resistor 6 having a large permissible current amount is required. Thus, there is a problem in that the current sensing resistor 6 is expensive and large in size.